This is decadent but so delicious! Read all the tips at the end of the recipe.
1.7kg (about 3½ lb) floury potatoes 2 large cloves garlic, peeled Salt 325ml (about 11 fl oz) cream 175ml ( about 6 fl oz) water Butter Freshly grated nutmeg Freshly ground white pepper (use black if you don’t have it) 1 Tbsp thyme leaves 200g (7 oz) gruyère cheese, grated
1 Preheat oven to 180°C (350°F). Butter a deepish ovenproof dish (3-litre/6 pint capacity). Peel potatoes and slice thinly on a mandoline or with a large sharp knife. Crush garlic on a board with a little salt, then mix it in a jug with cream and water.
2 Put one-third of the potatoes in the buttered dish. Grate a little nutmeg over top, season with a little salt and white pepper, and scatter with a little thyme. Cover with half the cheese, then make another layer of potatoes and cheese, seasoning as you go, finishing with a final layer of potatoes. Pour cream mixture over top. Season top of potatoes with a little more nutmeg, salt, white pepper and thyme.
3 Cover potatoes with a piece of baking (parchment) paper, then cover with a lid, or use baking paper and tin foil, and bake for 1 hour, or until tender. Remove lid and continue cooking for a further 20–30 minutes, or until golden on top. Serve hot.
This is seemingly an easy dish to make, but in fact there is an art to arriving with the potatoes beautifully tender coated with just enough creamy sauce.
The trick for a good potato gratin is to use a sturdy oven dish (one made of cast iron is ideal) so that you get a good crust all around the sides. I use a cast iron dish with the following measurements: 1.3-litre liquid capacity, 21cm diameter and 4.5cm deep.
The gratin will work with mid-season potatoes that are neither waxy or floury, or floury potatoes, but it is never that successful with waxy potatoes. Salt will stick to wet fingers, so use a teaspoon when sprinkling salt and seasonings over potatoes.
Covering the potatoes with baking paper is a great trick as it keeps in moisture helping the potatoes steam. There’s nothing worse than hard dried-out potatoes on top, and uncooked potatoes in the middle of the gratin.
Cheese is optional – it makes it richer, and ads some flavour, but the gratin is equally good without it.
Potato & Gruyère Cheese Gratin photograph by Aaron McLean http://www.aaronmclean.com